Clearance-setting mechanism



May 20, 1930.

G. A. DE VLIEG CLEARANGHSETTING MECHANI SM 2 SheetsShee-t 1 Original Filed May 15, 1926 VINVENTOR v Ecrnrd DEMIE v ATTORNEYS May 20, 1930. G." A. DE VLIEG 1,759,044

' CLEARANCE SETTING MECHANISM Original Filed May 15, 1926 2 Sheets-Sheet 2 INVENTOR ATTORNEYS anism of this character disclosed in my pending application, Serial No. 109,222, filed Patented May 20, 1930 PATENT OFFICE GERARD A. DE VIIIEG', OF ROCKFORD, ILLINOIS dLEARANCE-SETTING MECHANISM Originalapplication filed May 15, 1926, Serial No. 109,222. Patent No. 1,710,533. Divided and this application filed December 4, 1926. Serial No. 152,669.

The present invention relates to improvements in clearance setting mechanisms for rotary tools having a plurality of cutting edges, and has particular reference to a mech- May th, 1926, (Patent No. 1,710,533) on a method for grinding rotary cutters, of which this application is a division.

Rotary cutting tools having a plurality of generally longitudinal blades are commonly provided with a clearance on the back of each blade to prevent the heel from engaging the work, and to provide space for removal 13 of the refuse resulting from the machine operation. Preferably, a slight cutting clearance is provided at the cutting edge of each blade, and one or more relatively large relief clearances are provided on the back of the blade. To obtain a clearance, the cutter is initially adjusted into a position such that the grinding wheel will project into its circle of revolution, and the blade will contact with the face of the grinding wheel at an angle thereto. By angularly adjusting the cutter with reference to the rinding wheel, different clearances can be 0 tained.

The primary object of the present invention is to provide new and improved means which, after the cutter has once been adjusted into a predetermined relation to the grinding wheel, will serve as means whereby the cutter can be quickly and accurately adjusted into any one of a plurality of different positions for grinding diiferent clearances- I A further object resides in the provision-of means for adjusting the cutter angularly with respect to its driving element if the cutter is-rotatable during the cutting stroke, or with respect to its support if the cutter is not rotatable during saidstroke.

Still another object is to provide a novel clearance setting mechanism which is simple and inexpensive in construction, which can be easily applied to existing machines, which can be easily and quickly adjusted, and which is accurate in use. p

Further objects and advantages will become apparent as the description proceeds.

In the accompanying drawings, Figure 1 is a fragmentary front elevation, partially in cross section, of a grinding machine, in which a clearance setting mechanism embodying the features of my invention is incorporated.

Fig. 2 is a diagrammatic view showing the position of adjustment of the clearance setting mechanism to produce the cutting clearance. r

Fig. 3 is a diagrammatic view showing the position of adjustment of the clearance setting mechanism to produce the maximum or final relief clearance. 1

Fig. 4 is an end view of a blade provided with a cutting clearance and with a single relief clearance.

Fig. 5 is an endview similar to'Fig. 4, but showing a cutting clearance and two relief clearances. j

Fig. 6 is a longitudinal section through the headstock of the grinding machine, with the clearance setting mechanism attached.

Fig. 7 is a perspective viewv of the headstock with the clearance setting mechanism.

Fig. 8 is a detail view of the clearance setting mechanism, showing the cam and the dog in position to produce the maximum relief clearance.

Fig. 9 is a sectional view of the adjusting cam of the clearance setting mechanism.

' Fig. 10 is a fragmentary view of the setting finger for the cutter.

- While the invention is susceptible of various modifications and alternative constructions, I have shown, in the'drawings and will herein describe in detail, the preferred embodiment of my invention, but it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

'Referring to the accompanying drawings,

I have shown the preferred embodiment of myinvention incorporated in a relief grinding machine for reamers, and it is to be understood thatthe invention is equally applicable to a large varietyof relief producing machines. 1 r r The grinding machine comprises generally a horizontal base 11 having a vertical standard 12 on the rear. Rotatably mounted in the vertical standard 12 is a grinding wheel 13 which preferably is cup-shaped and which is inclined slightly from the perpendicular to the front of the machine.

hlounted for reciprocation on the front of the base 11 and across the face of the grinding wheel 13 is a carriage 14 on opposite ends of which are adjustably mounted a headstock 15 and a tailstock 16, having centers 1'7 and 18, respectively. ,An arbor 19 supporting a cutter 20 having blades 21 is mounted between the centers of the headstock 15 and tailstock 16.

Preferably, the headstock 15 is formed with a housing 22, the left end wall of which is provided with an integral inwardlyextending core 23 having a central bore 24. Mounted in the bore 24 is a socket member 25having a taper bore 26 in which the taper shank 2'? of the work center 17 is seated. Rotatably mounted on a bearing sleeve 28, fitting tightly over the core 23, is a gear 29 having a hub 30 on its left end, and having an annular flange 31 on its right end, concentric with the center 17 and projecting out from the right end o-f the housing 22. To prevent backlash, a brake shoe 32 is, pressed by a spring 33 against the hub 30 of the gear. The right end of the housing 22 is closed by concentric spaced ring members 34 and 35, secured respectively to the free end of the core and the housing 22, and engaging the inner and outer peripheral surfaces, respectively, of the flange 31.

The gear 29 meshes with a pinion 36 on a horizontal shaft 37 which is adjustable with the headstock 15 and which extends slidably through a gear housing 38 mounted on the left end of the carriage 14. The shaft 37 is connected through a train of change speed gears 39 in the housing 38 to a stub shaft 40. The stub shaft 40 is connected through a universal joint 41 with an extensible shaft 42 which is adapted to be driven in timed'relzn tion to the reciprocation of the carriage 14 by means not shown herein, but fully disclosed in my said co-pending application.

Means is provided for-operatively connecting the work arbor 19to the annular flange 31. This ineans comprises a cam member 423 ro ta'tably mounted on the shoulder of a screw bolt 44 threaded into the end'of the flange 31, and having a peripheral shoulder 45 on its inner end fitting against said flange. The cam member 43 is formed'with plurality of distinct arcuate surfaces, four surfaces (at, 0 and d in the present instance, which are locatedrespectively at progressively (greater distances from the center. A plurality of radial notches 4.6; one for each surface, are formeclzin the inner face of the shoulder 45, and are adapted to be selectively engageclxby'a plunger 47 slidably mounted in a bore 48 in the flange 31 and pressed outwardly by a spring 49 to hold the cam member yieldingly in any one of its four positions. A plurality of pins 50 projecting from the periphery of the shoulder 45 provide means by which the cam member 43 may be easily adjusted.

Rotatably mounted on or about the center 17, and extending into the ring member 34 is a drive sleeve 51 having a peripheral flange 52 intermediate its ends. An adjusting ring 53 is rotatably mounted on the sleeve 51, and is adapted to be adjustably secured against the inner side of the flange 52. In the present instance, a clamp screw 54 extends through an arcuate slot 55 in the lower side of the flange 52 into the adjusting ring 53, and is adapted to clamp the ring in position. A bolt 54 extends through an a-rcuate slot 55 in the upper side of the flange 52, and has a reduced threaded end portion threaded tightly into the ring 53. A washer 61 is slidably mounted on the bolt 54', and a small coil spring 62 is disposed on the bolt between its head and the washer, The spring serves to press the washer .61 against the flange 52 so as ito hold the flange and the ring 53 together with a constant pressure to facilitate ad justment of the ring when the clamp screw 54 is loosened. The ring 53 is provided with a dog 56 integral therewith and projecting into the path of the cam member 43. The (log 56 is adapted toengage anyone of the four cam surfaces a, b, c and cl depending upon the adjustment of the cam member. The outer end of the drive sleeve 51 is formed with a key member 57 adapted to interlock with a key member 58 on a dog '59, secured to the arbor 19. It will be evident that the cam member 43 and the dog 56 constitute an adjustable means in the driving connection between the arbor l9 and the gear 29 where by the arbor can berelatively adjusted into different angular positions about its axis.

To correctly locate the blades 21 of the cutter 20 with respect to the grinding wheel 13, an adjustable setting finger 60, movable into and out of operative position, is mounted next to the face of the grinding wheel, and is adaptedto be engaged by a blade of the cutter.

In operation, the setting finger 60 is initially located to position the cutter for grinding the cutting clearance or. After positioning the. cutter against the finger 60, the dog 56 is moved against the arcuate surface a,

' and is-clampcd to the flange 52 by tightening the screw'54. The cutter is now fixed with reference to the driving mechanism, and the se'ttingfinger can be moved into its inopera- I tive position. If: the cutter has straightblades, it is reciprocated across the face'of the grinding wheel to grind-the cuttingclearanceaand is indexedxperiodically to present difterent blades successively; to th grindi g inclination of the blades.

After the cutting clearances a, have been ground, the cutter is angularly adjusted by moving one of the three remaining surfaces of the cam member 43 into engagement with the dog 56. The surfaces Z), 0 and (Z will position the cutter respectively for grinding relief clearances 72, c and (Z. The specific relief clearances and the number to be ground depend on the character and size of the cut ter. In Fig. 4, I have shown a single blade provided with a narrow cutting clearance a at the cutting edge, and with a single relief clearance 0 back of said cutting clearance;

and in Fig. 5, I have shown a similar blade with a cutting clearance 0; and a relief clearance b and 0. While the cutter was initially adjusted for grinding the cutting'clearances, it willbe obvious that it might be initially positioned by proper adjustment of the setting finger for grinding other clearances.

It will be noted that the clearance set-ting mechanism makes possible a quick and accurate angular adjustment of the cutter after an initial setting. The device is. simple, sturdy, and easily adjusted.

I claim as my invention:

1. A clearance setting mechanism for rotary cutters having, in combination with a support, a center on said support for the cutter, a rotatably adjustable cam member mounted on said support and having a plurality of off-set arcuate cam surfaces, means for holding said cam member yieldingly in any one of a plurality of positions corre sponding to said cam surfaces, a sleeve loosely mounted on said center and adapted to be operatively connected for rotary movement with the cutter, said sleeve having a peripheral flange, a' ring member rotatably adj ustable on said sleeve next to said flange and having a dog adapted to engage said cam member, and means for clamping said ring to said flange, said cam member upon adjustment, serving to angularly adjust the cutter relative to said center and serving to hold the cutter in adjusted position relative tosaid support.

2. A clearance setting mechanism for rotary cutters having, in combination with a support, a center on said support for said cutter, a rotatably adjustable cam member mounted on said support and having a cam surface, means for holding said cam member yieldingly inany one of a pluralityof positions, and a member loosely mounted on said center and adapted to be operatively connected for rotary movement With the cutter,

said member having a dog adapted to engage said cam member, said cam member upon adj ustment serving to angularly adjust the cut ter relative to said center and serving to hold the cutter in adjusted position relative to said support.

3. A clearance setting mechanism for rotary cutters having, in combination, a support for the cutter, a member loosely mounted on said supportand adapted to be operatively connected to the cutter for rotary movement therewith, a cam member adjustably mounted on said support and having a plurality of offset cam surfaces, a cam engaging member rotatably adjustable on said first mentioned;

member and adapted to selectively engage said cam surfaces.

7 4. A clearance setting mechanism having, in combination, a stop, a cam member pivotally secured to said stop, said cam member? having a plurality of distinct offset'surfaces on its periphery, means for yieldingly holding said cam member in any one of a plurality of positions corresponding to said surfaces, means freely movable relative to said: stop and adapted to be connected to the work blank, and a cam engaging member rotatably adjustable on said means, said cam engaging and being adapted to selectively surfaces.

5. A clearance setting mechanism for rotary cutters having, in combination, a rotary drive member, an adjustable cam member mounted on said drive member for bodi ly movement about the axis of the latter, and a member freely mounted for rotation on said axis and adapted to be operatively connected to the cutter for rotary movement therewith,

member projecting across said cam member engage said s said last mentionedimember having a part;=---

adapted to co-act with said cam member, adjustment of said cam member serving to adjust the angular relationbetween said drive member and said last mentioned member.

6. A clearance setting mechanism for ro e;-

for the cutter, a member loosely mounted on said support and adapted to be operatively connected to the cutter for rotary movement therewith, a cam member adjustably mounted on said support, a cam engaging member rof tatably adjustable on said first mentioned member and adapted to engage said cam member.

8. A clearance setting mechanism having,

in combination with means for rotating a cutter, a cam member adjustable on said meansat oneiside of the axis of said means, said cam member having a cam surface, a member rotatably mounted on said means concentrically thereto, said last mentioned member being adapted to be connected to the cutter for rotatably adjusting the latter relative to said means, and a cam engaging memher on said last mentioned member disposed in eccentric engagement with said cam member, adjustment of said cam membcrserving to rotatably adjust said last mentioned member relative to said means to rotatably adjust thecutter. 9. A clearance setting mechanism comprising, in'combination, a rotary drivingmember, a rotary driven member, said members being coaxial, said driven member beingadapted to be ioperatively connected to :a rotary Work blank, a cam adjustably mounted on one of said members, and a cam engagingmember on the other of said first mentioned members, adjustment of said cam serving to adjust the angularrelation between saidfirst-mentioned as members.

10. A clearance setting mechanism comprising, in combination, :a rotary driving member and a rotary driven member, said members being coaxial and saiddriven memao ber being-adapted to be operatively connected to a rotary Work blank and a driving connection between said members, said connection comprising a rotatably adjustable cam mounted eccentrically on one of said members and 36 having a plurality of oif-set cam faces, and a camengaging member mounted on the other of said first-mentioned members and adapted to be brought selectively into engagement with said faces to adjust the angular relation between said two first-mentioned members.

In testimony whereof, I have hereunto affixed my signature.

GERARD A. DE VLIEG. 

